This is a request for funds to support the Molecular Biology Core, a major care facility of the UT Southwestern SDRC that is administratively linked with two molecular biology core support mechanisms outside the SDRC. This Core has been extraordinarily successful over the last four years in meeting its missions of: 1) providing basic molecular biologic techniques (e.g., PCR, Northern/Southern blotting, cDNA cloning) to SDRC investigators, 2) performing special molecular biology assays (e.g., special oligonucleotide synthesis, high-capacity DNA sequencing, homologous recombination) for SDRC investigators, 3) instructing SDRC investigators in the establishment and performance of required molecular biology techniques in their own laboratories, and 4) developing and adapting novel techniques within the Core facility (e.g., homologous recombination, in-situ PCR, representational difference analysis) and instructing SDRC investigators in their use. These missions have been met with considerable efficiency -- for example, high volumes of oligonucleotides and DNA sequencing have been delivered to SDRC investigators at far below outside commercial market costs. We seek funds to continue this service, expand certain elements within this Core and continue to provide overall guidance for molecular biological experimentation within the SDRC.